We discuss information loss from black hole physics in
AdS_3, focusing on two sharp signatures infecting CFT_2 correlators at
large central charge c: 'forbidden singularities' arising from
Euclidean-time periodicity due to the effective Hawking temperature,
and late-time exponential decay in the Lorentzian region. We study an
infinite class of examples where forbidden singularities can be
resolved by non-perturbative effects at finite c, and we show that the
resolution has certain universal features that also apply in the
general case. Analytically continuing to the Lorentzian regime, we
find that the non-perturbative effects that resolve forbidden
singularities qualitatively change the behavior of correlators at
times t ∼ S_{BH}, the black hole entropy. This may resolve the
exponential decay of correlators at late times in black hole
backgrounds. By Borel resumming the 1/c expansion of exact examples,
we explicitly identify 'information-restoring' effects from heavy
states that should correspond to classical solutions in AdS_3. Our
results suggest a line of inquiry towards a more precise formulation
of the gravitational path integral in AdS_3.